A Mansfield man was killed Friday evening when he hit a tree while riding a motorcycle in Norton, police said. Daniel Waldon, 52, was riding north on Newland Street around 7:15 p.m. when he crashed into the tree, police said. The responding officer administered first aid before Waldon was taken to Sturdy Memorial Hospital in Attleboro, where he was pronounced dead, police said. Norton police and State Police are investigating, the statement said.